Hi. I might as well make a visual tutorial for the particular method that I use to cutout objects from complex backgrounds but that will have to wait until later. For now here are the detailed instructions:
Open the file that contains the image(s) that you want to cutout
Create a new layer, select the Line / Curve tool (the color can be whatever you like), make the brush width at least 4 and start drawing on the inside edges of the object that you want to cut out.
Once the object has been drawn, make sure there are no open ends or gaps and then select the Paint Bucket tool and fill in the object using a tolerance level of 70%. The result should look like a silhouette of the object.
Now select Effects -> Object -> Apply Texture and open the original file again and reduce the Save Brightness all the way.
Now disable or delete the bottom layer and you've got yourself a nice, clean cutout of the object. ^_^